A Northwoods Almanac for 2/16 – 3/1, 2018
Sightings – Northern Shrike and White-throated Sparrow
Nancy Anderson spotted a northern shrike in her yard on 2/3 and noted: “We have many common redpolls at this time here in Lac du Flambeau, so we're thinking hunting is good for this predatory song bird.” She’s right. Around one’s home, northern shrikes are a short-lived thrill to spot. While they’re uncommon and beautiful, they are there for one reason only – to scout your feeders for their next meal.
|photo by Nancy Anderson|
Their Latin name, Lanius excubitor, means “butcher watchman,” a fitting tribute to their skill set, because they typically sit and wait to spot prey from an exposed hunting perch. We’ve watched them sit motionless above one of our feeders for many minutes waiting for a mouse or vole to venture from a hole.
The literature says they have the ability to spot motionless birds “frozen” on branches and to capture them before they move, which is not good news for the many songbirds that utilize this defense. They’re not strong direct flyers, but they don’t give up easily, often following prey into thick bushes. They’re also known to take down birds larger than themselves, including robins, jays, and doves.
They kill birds and other vertebrates by biting the nape of the neck and “disarticulating cervical vertebrae.” Northern shrikes have bilateral, subterminal tomial teeth on their upper bill which appear to penetrate between adjacent vertebrae, quickly damaging the prey’s nerve cord, thus paralyzing and killing it.
Bilateral: both sides. Subterminal: almost at the end. Tomial: a notch on the edge of the beak. They’re not “teeth” since no bird has teeth, but they’re like a tooth along each side of the beak. These “teeth” make for a prey’s quick death, which as any hunter knows is a good thing.
There are frequent reports of shrikes killing in excess of their food requirements. Bird banders tell me of shrikes getting inside their traps and killing all the birds. But shrikes will store food, so they’re just harvesting what’s available for later use, no different than humans putting food in the refrigerator for later meals.
On another note, we have a single white-throated sparrow spending the winter at our feeders. As a ground feeder wintering in deep snow country, this white-throated sparrow has to be severely challenged to survive. I wish I could ask him why he didn’t migrate to a warmer climate with less snow back in November.
The white-throat’s winter diet is mostly grass and weed seeds, thus the need to winter further south. But they also eat fruits of sumac, grape, highbush cranberry, mountain ash, and rose hips, all of which (except sumac) we have in our yard, so perhaps that explains this lone male staying put.
They also know how to dress for the winter – a white-throated sparrow has some 2,500 contour or body feathers in winter compared to summer's 1,500. So, the cold may not be too much of an issue for this little guy.
Update on the Clark’s Nutcracker
Mary and I were able to visit with a very gracious couple in Oneida County who have had a Clark’s nutcracker visiting their yard since the first of the year. The nutcracker is drawn to a deer carcass they have hanging from a tree, as for that matter are chickadees, nuthatches, and other birds – fat equals high energy in a cold winter.
|photo by John Bates|
As I wrote about in my last column, the nutcracker is a very rare visitor to Wisconsin, so this is a big deal in the birding world. The question that always arises when a bird is so far from its normal range is what will happen in the spring? Will the nutcracker know how to migrate back to its normal Rocky Mountain breeding habitat, or will it look around and say “What now?”
One day it will disappear from its winter restaurant, and unless banded and recovered, we’ll never know the end to the story.
Great Backyard Bird Count
The 21st Great Backyard Bird Count (GBBC) will take place February 16 to 19. This global event provides an opportunity for bird enthusiasts to contribute important bird population data to scientists so they can record changes over time. To participate, bird watchers count the birds they see for at least 15 minutes on one or more days of the count, then enter their checklists at birdcount.org.
Over its 3-decade history, the GBBC has expanded from a 2-country count (U.S. and Canada) to a global event. During the first GBBC in 1998, bird watchers submitted about 13,500 checklists from the United States and Canada. Twenty years later in 2017, an estimated 240,418 bird watchers from more than 100 countries submitted 181,606 bird checklists and reported 6,259 species – more than half the known bird species in the world.
The rules are easy:
Count birds for at least 15 minutes on any of the days or all: Feb 16, 17, 18, or 19.
Keep track of how long you counted and if you’re walking, how far you walked.
Go to your favorite spot or any spot. It doesn’t have to be a backyard – it can be anywhere.
Start a new count for each new place or time.
Enter your checklists at birdcount.org.
This can be as easy as you want it to be – lots of folks simply look out their windows and count their feeders from the warmth of their homes. And in the Northwoods in February, you’re likely to see more birds that way than taking a walk or driving around looking for birds. Our Christmas bird counts have proven this many times over. Please consider joining the count!
Nesting Has Begun!
As hard as it may be to believe, several bird species should now be nesting. Both great horned owls and gray jays are known to be incubating eggs by late February. Gray Jays nest during late winter in cold, snowy, and apparently foodless conditions, with eggs incubated at temperatures as low as -22°F. Nest building can begin in February, with clutches initiated as early as Feb 22 in Algonquin Park, Ontario, which is almost exactly the latitude of Minocqua. Interestingly, second broods or replacement nests are not attempted in May or June, the breeding period used by other boreal passerines. Gray jay nestlings are being fed before 80% of our migratory birds have even returned.
For great horned owls, females are able to maintain their eggs at incubating temperatures near 98°F, even when the ambient temperature is more than 70° colder. They’re able to incubate eggs successfully when outside temperatures are below -27°F. In one study, the eggs withstood the absence of the incubating female for 20 minutes at -13°F when the female joined her mate hooting at a neighboring male.
I was asked whether winter bird baths are a good idea or not. It’s been said that birds can get their feet wet in these baths, and then freeze to the metal rods on bird feeders. I have heard of this occurring on two occasions over the last 25 years, but that’s a pretty small percentage. My sense is that the advantages far outweigh the risks. After all, birds can get their feet wet in a host of other ways in the winter – we do have open water in many creeks, and dripping icicles are common drinking sites for birds – so, bird baths are not exposing birds to some novel occurrence.
The simplest way to provide water in winter is to set out a very shallow plastic pan at the same time each day, and bring it in when ice forms. If you want to keep a birdbath ice-free, some birdbaths come with built-in, thermostatically controlled heaters.
Some simple, common sense rules include never adding antifreeze to the birdbath – it’s poisonous to all animals. Don’t use a sugar solution, either: it can saturate and matt a bird’s feathers leaving it susceptible to hypothermia. Just use plain water.
It’s also important to change the water every day or two. Bathing birds may leave behind dirty feathers and droppings, making the bath increasingly unsanitary for other birds.
The new moon occurred yesterday, 2/15. Check the night sky tonight because this is the time of year when the brightest accumulation of stars can be seen annually. Look for constellations like Orion, Sirius, Gemini, Auriga, and Taurus, all of which contain first-magnitude stars.
Venus rises before dawn late in the month in the southwest, and will climb higher and higher as the spring returns. For right now, however, the morning planets are Saturn, Mars, and Jupiter, all of which can be seen in the southeast before dawn.
As of 2/27, we will be receiving over 11 hours of sunlight – hooray! It’s getting lighter every day.
February has no full moon this year. The next full moon occurs on March 1, and like January, March will have two full moons, the second one occurring on 3/31.
Thought for the Week
“We ourselves seldom comprehend the moment at hand. So, we turn to history, the one element of our lives it is possible to fix on. Or we turn to principle. Or we turn to nature. There we find, amid the silence and mystery, order and structure, the sense that life is not simply random.” – Paul Gruchow